Deepening the uncertainty clouding Kenya’s future, Raila Odinga dismissed the president as “the product of a fraud” after Mr Kenyatta was handed an equivocal mandate a day earlier when he was declared the winner of a vote boycotted by the opposition.

As many as 14 people have been killed since last Thursday’s election, adding to the scores of people who died before Mr Kenyatta’s first victory in August was overturned by the supreme court.

But Mr Odinga’s call to mass action perversely helped to calm tensions after he chose not to call for immediate demonstrations. Many of his supporters who had gathered on the streets drifted home, with some admitting confusion over the opposition’s lack of clear direction.

Instead, Mr Odinga appeared to be preparing for a longer struggle against his rival that he said was aimed at forcing a third election that the whole country would judge as credible. Failure to do so, he warned, would see the country drift towards despotism.

“This election must not stand,” he said. “If allowed to stand, it will make a complete mockery of elections and might be the end of the ballot as a means of instituting government in Kenya.

“If there is no justice for the people, let there be no peace for the government.

Unveiling a key part of his strategy, Mr Odinga said the opposition would soon convene a “people’s assembly” that would debate constitutional amendments which would then be sent to regional assemblies for ratification.

Such a move is likely to be interpreted by the government as an attempt to create parallel power structures, setting the stage for further confrontation.

Britain and other western powers have called for political dialogue to resolve the impasse, amid fears that the violence could disintegrate into ethnic bloodshed. At least two people have already been killed in fighting between tribes loyal to the government and those supporting the opposition.

While not ruling out the possibility of talks, neither the president nor Mr Odinga have been prepared to commit to them either.

With the opposition also insisting that it would not itself mount a legal challenge to the latest election, amid fears that the supreme court had been intimidated into losing independence, analysts warn that Kenya’s political crisis risks rapidly becoming intractable.

Although Mr Odinga would appear to have a rich repository of support after just 39 percent of Kenyans took part in last week’s vote, it remains unclear how strong the appetite genuinely is in opposition areas for a prolonged confrontation with the government.